【摘要】 在我国农业快速发展的大背景下,盐碱地严重制约了土地的有效利用和作物的生长发育,如何有效改良盐碱地,已成为农业生产的一个紧迫问题。粉煤灰作为一种大宗工业固体废弃物,已被证明具有广泛的农用价值,在盐碱土壤改良中具有潜在的应用前景。通过系统回顾粉煤灰的产生与理化特性、粉煤灰作用下盐碱土壤的理化性能、粉煤灰的潜在危害与土壤调理等方面的研究成果,总结了粉煤灰的特点及潜在性能,探讨了在盐碱土壤改良中的机理,阐述了粉煤灰在土壤改良过程中所发挥的作用。指出盐碱土主要由高盐分引起土壤颗粒聚集,使得土壤紧密,容重大、易板结、透气透水性能差,导致微生物难以生存,养分难吸收、难积累、难分解。粉煤灰因其特有的粒小质轻、多孔性以及含有硅铝钙等元素的特点,可从物理上疏通盐碱土堵塞的孔隙、促进团聚体形成、降低容重,从化学上促进离子淋溶与盐碱土发生离子交换、降低p H值与钠离子含量,复配有机肥、腐殖酸、活性污泥等可以弥补盐碱土养分、有机质不足的问题。在上述基础上,指出粉煤灰改良盐碱地未来需要努力的方向与攻克的难点:(1)对粉煤灰进行科学的物化分析,更有针对性地进行多元改性处理和复配功能材料,结合各种类型盐碱土提出综合性利用方案;(2)对粉煤灰改良盐碱土前后进行环境污染评价,尤其是重金属赋存特征及形态评价,确保土壤利用的安全性与科学性;(3)以粉煤灰和盐碱土多年田间实际应用结果,制定相关产品标准、技术规程和评价体系。通过以上研究,进一步推动农业生产中盐碱土壤改良实践和粉煤灰资源利用提供参考和建议,实现粉煤灰环保化资源化利用。更多还原

【Abstract】 In the context of rapid agricultural development in our country,saline-alkali soil has seriously restricted effective land use and crop growth. Therefore,how to effectively improve saline-alkali soil has become an urgent problem in agricultural production. Fortunately,fly ash,an important industrial waste resource,has been proven to have extensive agricultural value and has potential applications in saline-alkali soil improvement. Through a systematic review of the production and physicochemical properties of fly ash,the physicochemical properties of saline-alkali soils under the influence of fly ash,the potential hazards of fly ash,and research on soil conditioning,the characteristics and potential performance of fly ash have been summarized. The mechanism of fly ash in the improvement of saline-alkali soils has been explored,and the role of fly ash in the process of soil improvement has been elaborated. The research shows that saline-alkali soil is mainly caused by high salt content,which leads to soil particle agglomeration,making the soil compact,heavy in weight,prone to compaction,and difficult to breathe and drain. This ultimately leads to the difficulty of microbial survival,nutrient absorption,accumulation,and decomposition. Fly ash,with its unique characteristics of small particle size,light weight,porosity,and the presence of silicon,aluminum,and calcium elements,physically unblocks the clogged pores in saline-alkali soil,promotes the formation of aggregates,reduces bulk density,and chemically promotes ion leaching and ion exchange with saline-alkali soil,reducing p H value and sodium ion content. When combined with organic fertilizer,humic acid,and activated sludge,it can make up for the deficiencies of nutrients and organic matter in saline-alkali soil. On the basis mentioned above,the future directions and challenges to be addressed in the improvement of saline-alkali land using fly ash are pointed out:(1) Scientific physicochemical analysis of fly ash should be conducted to more effectively carry out multi-component modification processing and compound functional materials,and comprehensive utilization schemes should be proposed in combination with various types of saline-alkali soils;(2) Conduct environmental pollution assessment before and after the improvement of saline-alkali soil with fly ash,particularly the evaluation of heavy metal occurrence characteristics and forms,to ensure the safety and scientific utilization of the soil;(3) Based on the actual field application results of fly ash and saline-alkali soil for many years,formulate relevant product standards,technical specifications,and evaluation systems. Through the above research,it provides reference and suggestions for further promoting the practice of saline-alkali soil improvement and the utilization of fly ash resources in agricultural production,thereby achieving the environmentally friendly and resourceful utilization of fly ash.更多还原